Weak localization in pure and Cr-doped MoS2 macroparticles probed through a low field magnetoimpedance effect

Abstract

Globular MoS₂ with Cr doping, exhibiting a flake-like texture, was studied through AC magnetoelectric transport to identify weak charge localization that is not identified using magnetic measurements, in order to establish inhomogeneity-driven magnetoelectric coupling. Hydrothermally synthesized MoS₂ had a mixed 2H/1T phase in native conditions. Upon doping, the proportion of the 1T phase increased. To probe inhomogeneity-driven magnetoelectric coupling and localization, magnetoimpedance studies were carried out to establish an MR of 110% at 100 Hz frequency for pure MoS₂. For the doped condition, they were −7% for MoS₂–Cr 5%, 1.9% for MoS₂–Cr 10% and 58% for MoS₂–Cr 15%. The feeble spin order was lost in all the compounds at low temperature from 17 to 51 K, as shown in magnetization studies, developing a blocking behavior in resistivity. Weak charge localization was detected that changed the polaronic radius in MoS₂ and decreased its width with doping according to relaxation studies. The change in activation energy and the effect of the magnetic field on the bulk resistivity and relaxation time revealed that the strength of localization was weaker following doping. The change in relaxation time of MoS₂ across doping concentrations with the application of a magnetic field at a given temperature confirms the spin accumulation/deaccumulation process. This establishes inhomogeneity-driven weak localization in Cr-doped MoS₂.